LA2A Tube Replacement - 12BH7A

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airtech

Well-known member
Joined
Jul 19, 2005
Messages
79
Location
Long Beach, California
I've got a bad 12BH7A (Electro Harmonix) in one of my LA2A's that I built and was wondering if I could use one of my 6414 tubes that I have from Manley.

I tried it out for about 10 minutes and it worked fine, but wasn't sure if it would cause any more problems.

Thanks,
Nate
 
Buy a tesla 12bh7 tube which have gotten great reviews when used with La2a than use a tube of a different model.
 
Just wanted to use some tubes that I already have.  I read online that the 6414 was similar to the 12bh7a.  Thanks for the tip on the Tesla 12bh7a.  I did a search and couldn't find a tube topic for the la2a.  Could you send me a link to that discussion?

Nate
 
Might work in the short term but you might fry it. 200v max on the plate (as compared to 300v for a 12bh7a), and schematic says it is getting 220v.

This is your friend:
http://www.nj7p.org/Tube.php
 
Also, beware that the 6414 draws more heater current. Depending on the safety margin of your own PSU transformer, it may be an issue, or not...

Axel
 
I've got a Hammond 269X with 2amps @ 6.3v for the LA2A.  Between the 4 tubes, it looks like the total draw will be 1.5amps (12ax7's=.6amps, 6aq5 = .45amps, 6414 = .45amps) on the heater's.

Is that correct?

Thanks,
Nate
 
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